Connectors are used for connecting a plurality of solar cell modules in series at a site where such solar cell modules are installed. Some types of such connectors have a built-in bypass diode for bypassing a solar cell module. Technical attempts to improve the connectors have been made to make them small in thickness. For example, Japanese Patent No. 3,498,945 discloses in its specification a technique, according to which a bare chip diode, which is not provided with a protective package and, therefore, bare, is used, and, when a box of a solar cell module connector is filled with resin, the bare chip diode is also packaged together. According to this technique, however, when a solar cell module with which a connector is connected in parallel is not generating electric power, current from other solar cell modules connected in series with that inoperative solar cell module flows through the diode of the connector connected in parallel with that inoperative solar cell module. In such case, the diode generates heat, but the generated heat cannot be dissipated sufficiently. A technique trying to improve this drawback is disclosed in Patent Literature 1.
According to the technique disclosed in Patent Literature 1, the interior of a box made of an insulating material is divided into three zones juxtaposed in parallel with each other. The one of the three zones at one end of the juxtaposition is a terminal zone for solar cell module leads, the center one is a diode heat dissipating plate zone, and the other end zone is a terminal zone for input/output cables. An opening is formed in the bottom wall of the diode heat dissipating plate zone, and four rectangular heat dissipating plates are disposed in line in the opening. Diodes are mounted on the successive three heat dissipating plates from one end of the line. Each diode includes a diode semiconductor chip embedded in an insulating mold. The anode of the semiconductor chip is connected to an external conductor exposed on the bottom of the mold, and the cathode is led out of the mold by means of a lead. The external conductors of the three diodes are attached on the above-stated three heat dissipating plates, respectively, with the cathodes connected to the respective adjacent heat dissipating plates, resulting in series connection of the three diodes. Terminals for the module leads are disposed with their one ends located at the edge portions of the respective heat dissipating plates on the solar cell module lead terminal zone side thereof, and with the other ends located within the solar cell module lead terminal zone. Also, terminals for the input/output cables are disposed, with their one ends located at the edge portions on the input/output cable terminal zone side of the heat dissipating plates at the opposite ends of the line, and with the other ends located within the input/output cable terminal zone. In this state, the diode heat dissipating plate zone is filled with an insulating resin so that the respective diodes are embedded in it. After being filled, the box is fixed to the rear side of a solar cell panel, with the heat dissipating plates exposed on the bottom wall side of the box contacting the solar cell panel via a heat conductive, electrically insulating sheet, A solar cell module is connected to each solar cell module lead terminal by the associated solar cell module lead, which results in parallel connection of each diode with one of the solar cell modules. The input/output cables are connected to the input/output cable terminals so that current can be supplied to or derived from the respective solar cell modules. The solar cell module leads are soldered to the solar cell module lead terminals, and the input/output cables are also soldered to the input/output terminals. After that, an insulating resin is placed in the solar cell module lead terminal zone so that the solar cell module leads and the solar cell module lead terminals are embedded in the resin, and an insulating resin is placed in the input/output cable terminal zone so that the input/output cables and the input/output cable terminals are embedded in the resin.
[Patent Literature 1]JP 2005-209971 A